The present invention relates to a device for the car body (2) of which is supported by a spring action (3, 3') on at least one undercarriage (4), having a transverse compensator (12) which can be controlled via a control circuit (24) for shifting the car body transverse to the undercarriage, in accordance with the preamble to claim 1.
Such a device for compensating for centrifugal forces, known for instance from DE-OS 40 40 047, referred to in the following as a transverse compensation device, is used among other things on railroad cars and driving units of railway trains. In this case, as a rule, the body of the car is supported via pneumatic cushioning in vertical and horizontal direction on two trucks and, in addition, the transverse compensation device is provided between the body of the car and the trucks.
The known device has a hydraulic or pneumatic cylinder the working section of which, for instance the cylinder, acts on the truck, while the other working section, in this case the piston, is articulated to the body of the car. The axis of action of the cylinder is, in this connection, transverse to the longitudinal axis of the rail vehicle. Ordinarily, such trains are equipped with a car-body inclination system by which the car body, upon passing over a curve, can be so inclined towards the inside of the curve as a function of the radius of curvature of the curve and of the speed of the vehicle, that the fewest possible lateral forces act on the passenger. This technology therefore, when taking as basis the maximum possible lateral acceleration on the passenger without loss in the comfort of travel, permits substantially higher speeds around curves than with trains which are equipped with a traditional undercarriage.
Regardless of whether a rail vehicle is or is not equipped with the car-body inclination system, the car body can be actively displaced laterally with respect to the truck by a transverse compensation device. The car body is held in approximately its central position by the transverse compensation device despite the centrifugal force acting on it, so that the transverse spring action of the rail vehicle upon travel straight-ahead and travel around a curve lies in approximately the same region of its characteristic curve in which a weaker spring action is obtained than in a region in which the car body is displaced strongly laterally and rests against rubber bumpers having a steep characteristic (hard cushioning). Furthermore, the axis of sway of the car body can be set by the transverse compensation device at a predetermined (desired) position. The axis of sway is the virtual axis of rotation which extends parallel to the longitudinal direction of the vehicle and around which the car body turns upon travel around curves due to the centrifugal force which acts and possibly due to the action of the car-body inclination system. Ordinarily, it is attempted to set the axis of sway at approximately seat level or, more precisely, at the level of the passenger's stomach. In this way, assurance can be had even with high speeds around curves that the feeling of well-being of the passenger is not impaired by the effects of centrifugal force.
From EP-A 0 592 387, a transverse spring-action device is known with which, in a hydraulic variant, two hydraulic cylinders which are arranged in opposition to each other are provided and can be controlled so as to increase, when necessary, the transverse spring forces produced by the secondary spring action upon quasi-static transverse displacements of the car body.
Upon the use of said systems, it has been found that they are fully capable, upon travel around curves, of intercepting the quasi-static centrifugal forces caused by the centrifugal acceleration or minimize their negative effects on the passenger. On the quasi-static centrifugal forces, however, there are regularly superimposed dynamic forces which are transmitted to the car body by, for instance, unevenness in the track or by so-called passive forces, i.e. swinging motions produced by the rail vehicle itself.
In the case of rapidly responding transverse compensation systems these swinging motions can lead to corresponding reactions in the control circuit, so that, under given conditions of travel, and particularly when traveling around curves, there may be continuous changes in the position of the car body transverse to the undercarriage, so that the smoothness in travel of the rail vehicle on curves may not satisfy the high demands made.
If, however, the control is made so slow that it does not respond to the dynamic swinging, the desired comfort in travel can also not be obtained.